Add tenant-based conditional rendering for top-right "Login" link

[jeremyf]

From @ndroark

1. Have Hyku staff using the ReShare Hyku model be trained to use the Administrator login at the bottom of the UI to access staff functionality.
2. For ReShare use only, remove the Login at the top right hand corner as that login is linked to patrons accessing Hyku and with ReShare patrons will not be accessing their digital loans that way - they will come in from an already authenticated ReShare point which passes that to Hyku for them to access the doc.

As part of conversation: https://assaydepot.slack.com/archives/C0313NKC08L/p1697646938457559

Acceptance Criteria

• Add a tenant based feature flipper to say "Show General Login Link at Top Right of Page"; by default this is on. For Reshare we will instruct them to turn that feature off.

Screenshot

Testing

Test combinations of flipper status, show page theme, and type of user

Turn Flipper on or off: log in as admin user, navigate to admin/features, toggle flipper
Reshare on or off: log in as admin user, navigate to admin/appearance, themes tab, and Select via Show Page Theme
Log on or off: use options in footer if hidden from top right menu

Flipper On, Reshare On, Admin User

• Log in as an admin user
• Select Reshare theme & verify flipper is on
• Navigate to home, dashboard, catalog search, work show, and collection show pages
  • All pages show normal links in top-right

Flipper off, Reshare On, Admin User

• Turn flipper off
• Navigate to home, dashboard, catalog search, work show, and collection show pages
  • All pages show normal links in top-right

Flipper off, Reshare Off, Admin User

• Switch to a show theme other than Reshare
• Navigate to home, dashboard, catalog search, work show, and collection show pages
  • All pages show normal links in top-right

Flipper off, Reshare Off, no user

• Logoff
• Navigate to home, dashboard, catalog search, work show, and collection show pages
  • There is no login option at top right... only language dropdown appears

Flipper off, Reshare Off, non-admin user

• Log in as non-admin user
• Navigate to home, dashboard, catalog search, work show, and collection show pages
  • All pages show only dashboard link
• Log off

Flipper off, Reshare On, non-admin user

• Log on as admin user
• Switch to Reshare show page theme
• Log off
• Log in as non-admin user
• Navigate to home, dashboard, catalog search, work show, and collection show pages
  • Work show page has only language dropdown
  • All other pages show only dashboard link
• Log off

Flipper on, Reshare On, non-admin user

• Log on as admin user
• Turn flipper on
• Log off
• Log in as non-admin user
• Navigate to home, dashboard, catalog search, work show, and collection show pages
  • Work show page has only language dropdown
  • All other pages show only dashboard link
• Log off

Flipper on, Reshare Off, non-admin user

• Log on as admin user
• Switch to non-Reshare show page theme
• Log off
• Log in as non-admin user
• Navigate to home, dashboard, catalog search, work show, and collection show pages
  • Work show page has only language dropdown
  • All other pages show normal links

Sample Screenshots after changes

With Flipper on

Reshare show page, non-admin

Reshare show page, admin

With Flipper off

Reshare show page, non-admin

Reshare show page, admin

Home page, not logged in

Home page, admin

Home page, non-admin

[kirkkwang]

QA RESULTS ✅

Feature flipper option is present

When it's off I don't see a login link at the top

When it's on i see the login link